A Simple Balance/Volume Control

[downhere]

I was looking for a way to build a little remote volume/power control for my amp. Thinking of using the Project 01 "A better balance control" circuit for this, with a small project box, and an old extension wire as an already cabled input and output.

The plans do not state clearly how the balance pot actually works. I'm assuming it increases the volume on one channel? The Volume pot will be double gang. How would the balance pot be connected for stereo?

 

[downhere]

Also, how do you actually wire those 3 pin headphone jacks for a balance control. there's a shared ground. are there any modifications I should make to the circuit?

 

[grataku]

Are you referring to one of the ESP projects, right?
I haven't read that yet but, on a hunch, you would probably need to connect the dual balance pot with the ground on opposite ends so that the two chennels get equally attenuated when the dial is in the middle and when you move away from the center one channel gets more attenuated and the other gets enhanced (ok, attenuated less). It would make sense to use linear pots for this.



[Edited by grataku on 11-21-2001 at 02:42 PM]

 

[paulb]

I looked at the "Better balance / volume control" circuit. This circuit can only reduce the signal, not increase it. Both pots are dual gang. The balance pot must be a linear taper, while the volume pot must be logarithmic / audio taper. The balance control's sections are wired oppositely for each channel, so that as one channel's volume is increased, the other channel's is being decreased.
I didn't understand your question about headphone jacks. Are you trying to place the volume control just ahead of the headphone, without an amplifier inbetween? The volume / balance circuit is intended to drive a high impedance load such as an amplifier, not a low-impedance load like headphones. If you want to control the headphone volume directly, without an amp, the circuit will depend on the impedance of your headphones.

 

[Helix]

NO, the volume pot is a linear taper with a resistor shunted accross it to give the response graph thats described.

 

[paulb]

Helix,
Read on in the article. The first circuit ("Better Volume Pt. 1") is as you say, converting a linear taper to a log one.
The "Better Balance Control" circuit uses a log taper pot for the volume, "For example: VOL = 10k log, BAL = 25k lin"

 

[Helix]

I interpreted the diagram wrong, I thought, after looking at the circuit for the ‘better balance’ control (fig. 5) the reader can then go and bolt the 'better volume' control idea on to it.